#pragma comment(linker, "/STACK:10000000")
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <set>
#include <map>
#include <cstdio>
#include <cassert>
#include <string>
#include <cstring>
#define ldb long double
#define LL long long
#define fi first
#define se second
#define fill(a, c) memset(a, c, sizeof(a))
#define sqr(a) ((a) * (a))
#define nextLine() {int c = 0; while((c = getchar()) != 10 && c != EOF);}
#define getBit(mask, k) (((mask) / pw[k]) % pw[1])
#define setBit(mask, k, l) (((mask) / pw[k + 1] * pw[1] + (l)) * pw[k] + ((mask) % pw[k]))
#define debug(a) cerr << #a << " = " << a << " ";
#define debugl(a) cerr << #a << " = " << a << "\n";
const ldb LDINF = 9128739847123.00;
const ldb eps = 1e-9;
const int INF = 1 << 30;
const ldb pi = fabsl(atan2(0.0, -1.0));
using namespace std;

LL n;
int k;
int a[1110];


void Load()
{
	cin >> n >> k;
	for (int i = 0; i < k; i++)
	{
		cin >> a[i];
	}
	sort(a, a + k);
	reverse(a, a + k);
}
const int MAXN = 100000;
LL dp[MAXN][101];

LL go(LL m, int i)
{
	if (m == 0) return 0;
	if (i == k) return m;
	if (m < MAXN && dp[m][i] != -1)  return dp[m][i];
	if (m < MAXN) dp[m][i] = 0;
	LL res = 0;
	res = go(m, i + 1) - go(m / a[i], i + 1);
	if (m < MAXN) dp[m][i] = res;
	return res;
}

void Solve()
{
	memset(dp, -1, sizeof dp);
	cout << go(n, 0);
}

#define file "e"
int main()
{
	#ifndef ONLINE_JUDGE
		freopen(file".in", "rt", stdin);
		freopen(file".out", "wt", stdout);
	#endif
	Load();
	Solve();
	return 0;
}
